Question

two blocks of the mass M kg and 2,5 kg respectively are connected by a light in extensible string. the string runs over a light frictionless pulley. the blocks are stationary
a) calculate the tension in the string

Answer 1

To find the tension in the string, we can consider the forces acting on each block separately.

For the block with mass M:
- The force acting downwards is its weight, which is equal to Mg.
- The tension in the string acting upwards.
- The net force acting on the block is: T - Mg = 0 (since the block is stationary)

For the block with mass 2.5 kg:
- The force acting downwards is its weight, which is equal to 2.5g.
- The tension in the string acting upwards.
- The net force acting on the block is: T - 2.5g = 0 (since the block is stationary)

Now we can solve the above equations simultaneously to find the value of T:
T - Mg = 0
T - 2.5g = 0

From the first equation:
T = Mg

Substitute this back into the second equation:
Mg - 2.5g = 0
Mg = 2.5g
M = 2.5 kg

So, the tension in the string is equal to the weight of the block with mass M, which is 2.5g or 24.5 N.